Utilities: Add hard-coded try_compile result for libarchive strnlen check

libarchive 3.5.1 checks for strnlen.  It is available on all Windows
platforms.

Utilities/cmThirdPartyChecks.cmake

@@ -180,6 +180,7 @@ if(WIN32)
   set(HAVE_STRERROR_R 0)
   set(HAVE_STRNCMPI 0)
   set(HAVE_STRNCPY_S 1)
+  set(HAVE_STRNLEN 1)
   set(HAVE_STROPTS_H 0)
   set(HAVE__STRTOI64 1)
   set(HAVE_STRTOLL 1)